971. The root-noun used as infinitive

More special rules as to the various formations are as follows:

The root-noun used as infinitive has the same form (except that it does not take an added t: 383 f), and the same accent, both when simple and when combined with prepositions, as in its other uses. In the very great majority of instances, it is made from roots ending in a consonant; but also from a few in ā (khyā, dā, dhā, pā?, mā, yā), from two or three in i- and u-vowels (hi, mī, bhū), and from one or two in changeable ṛ, which takes the ir-form (tir, stir).

a. The roots in ā form the accus. in ām, the dat. in āi, the abl. in ās (understanding avasā́ before ā́ as for avasā́s and not avasāí in RV. iii. 53. 20), and the locative in e (only two examples, of which one is perhaps better understood as dative).